The Germans were ahead in most scientific fields from the start of WW2 and to the finish. The fields of science where the Germans were clearly ahead until the very end were aerodynamics (And physics in general actually), chemistry & electronics.
Germany had actually been the leader in technology since way before WW2, and continued to be so until the end of WW2, after which it still continued to be the leader in many areas right up till today actually.
Ever heard of the University of Göttingen and the labs there ? Most of the great mathematicians & phycisist of the 19th & 20th century went there. Or how about the Kaiser Wilhelm Institute, Max Planck Institute etc etc ? I guess you never heard of these either?
The Laboratory of Göttingen was the main center of theoretical and mathematical aerodynamics and fluid dynamics research from soon after 1904 and till the end of WW2, completely leading the way throughout WW2.
Because of this, since 1904 and throughout WW2, the Germans were ahead in aerodynamics, esp. high speed aerodynamics, Adolf Busemann & Ludwig Prandtl being responsibe for the greatest advances in areodynamics in history. Ludwig Prandtl, the farther of modern aerodynamics, coining the term boundary layer and founding modern mathematical aerodynamics. Prandtl was the absolute & undisputed leader in the field of aerodynamics/fluid dynamics throughout the war.
Adolf Busemann was the foremost expert in supersonic aerodynamics, and with the help of Prandtl he was the first to discover & establish the characteristics, advantages & disadvantages of the swepped wing. Hence why the Germans were deploying and designing swepped winged jet a/c during WW2, long before anyone else. The famous German designer Hans Multhopp was also an expert in this area.
Hence why the Germans were fielding the best fighters and most advanced a/c of WW2, the below examples being completely unrivalled:
Ta-152H & C
FW-190 D-12 & 13
The German advances in aerodynamics was also the reason why they were the leaders in ballistics research and designs, designing & producing the best projectiles of WW2. German rifles, machineguns etc etc were firing heavy boattailed spitzer projectiles (Designation: FMJ-BT) with very high Ballistic Coefficients, and many other specialized types, while nearly all other countries, including the US, still used flat based Spitzer bullets from the first world war. Spitzer bullets (Sharp pointed bullet) are a German/French design btw and were revolutionary in WW1.
German snipers could because of their better and more accurate projectiles also hit their targets more precisely at longer ranges than Allied snipers, a great tactical advantage on the open battlefield.
The Germans were also the leaders in rocket science, being the first to deploy self guided ballsitic missiles and air to air rockets.
Germany was also the leader in radar & infrared techonology, producing the best infrared imaging and being the first to deploy infrared equipment on smallarms & AFV's, a good number of vehicles (Inclduing the Pzkpfw.V Panther) being equipped with this in late 44 on the western front and enjoying amazing success.
And like we all know the Germans were also waay ahead throughout the war when it came to designing and building tanks, fielding the unrivalled Pzkpfw. VI Ausf.B King Tiger & Pzkpfw. V Panther and their subvariants.
On top of this the Germans were also the undisputed leaders in smallarms & gun design, designing & building the best & most powerful guns of WW2, most notably the unrivalled examples below:
MG-42, the best machinegun of WW2 and all time.
MG-34, the second best machine gun of WW2.
FG-42, one of the most advanced smallarms of WW2, a supurb LMG.
StG.44, THE best smallarm of WW2.
M98, the best bolt action rifle of all time.
128mm KwK/PaK 44 L/55 & L/61, the most powerful AT gun of WW2.
88mm KwK/PaK 43 L/71, the best tank & AT gun of WW2.
75mm KwK/PaK 42 L/70, the second best tank gun of WW2.
170mm K-18, the best heavy artillery piece of WW2.
And the list goes on....
Furtermore the Germans were producing the best & most precise optics in the world, Zeiss & Dialytan developing and providing optics for tanks, smallarms, guns, U-boats etc etc of unrivalled quality & precision.
And talking about U-boats, again the Germans were way ahead with their revolutionary electro boats, the type XXI & XXIII.